I have had the 2100's for years now, I still rate them as high quality tables. However, and this for some people may be a big however, the platter doesn't sit perfectly flush in the table, therefore you may feel a slight "wobble" when rocking the plate back and forth. No problem really except it makes it harder to control slipping beats by touching the record or the platter to slow donw/speed up. It forced me to learn pitch only corrections which has proved very good for my mixing. Scratching is also difficult but in no way is it impossible.

Between 2100 and 2400, having used both I find no difference other than aesthetics, yes the 2400 looks better but not by much, functionality is exactly the same (who needs 78rpm?) and if there is a difference in torque it is not noticable. So if its good tables at a cheap price you want then I would recommend the 2100's (just don't get a Gemini mixer to match them, their mixers suck!).